In the course of developing an electronic product, once an initial design for an electronic circuit is settled upon, a precise and detailed listing of each element of the circuit is completed and a proposed layout of a printed circuit board upon which to assemble the elements is developed. The printed circuit board is then fabricated and a first prototype of the proposed circuit is assembled and tested. Typically, the circuit design is then refined through an iterative process as more is learned about the circuit's behavior. During this iterative process, a succession of printed circuit board designs must be fabricated and circuits assembled as the design evolves. Assembly of each of the successive test circuits can be very time consuming; the assembly of a complex circuit may require weeks of technician time. Thus, there is a need for a quick and accurate way to test circuits without going through the process of repeatedly laying out and fabricating printed circuit boards.
Attempts have been made to develop circuit prototype wiring systems, and a number of prototype wiring systems have become available. Perhaps the simplest of these systems is a push-in board system which allows certain electronic components to be connected without soldering by pressing them into commonly connected retentive sockets. While this system allows quick and easy assembly of a prototype circuit, except in the case of very simple circuits, it may not provide a reliable representation of how a circuit will preform once laid out on a printed circuit board. The failure of this system to reliably predict performance in the case of more complex circuits results from the system's inability to properly model nodes as they will occur in a circuit under various frequency and current conditions once the circuit is assembled on a printed circuit board.
Another prototype wiring system of the prior art allows components to be soldered to a pre-built printed circuit board such that the components can then be connected with wires. While this system provides better circuit performance than the push-in type system, it is, none the less, awkward and does not provide a reliable prediction of the performance to be expected from a circuit when mounted on the printed circuit board in its final configuration.
As the frequency at which a circuit operates is increased, performance of the circuit becomes increasingly affected by electronic components in its environment, including components of the circuit itself, components connected to the circuit, and components completely independent of the circuit. This relational effect becomes very substantial in the case of circuits, such as those of microprocessor devices of the present art, which operate at high clock speeds. When designing printed circuit boards for such applications, the relational effect may be minimized by including a special conductive layer, generally referred to as a "ground plane layer" or "power plane layer", within the board. Such ground plane layers allow circuit designers to control the interaction of ground nodes in the circuit.
Current level also has an effect on ground nodes. In the design of circuits for relatively high power applications, such as those associated with power supplies and motor drives, it is absolutely necessary to provide a ground plane layer. Further, in many cases, it is necessary to provide multiple ground plane layers in the design of such circuits.
Thus, to allow proper modeling and reliable prediction of the performance of the final production version of printed circuit board mounted circuits for high power and high frequency applications, it is necessary that a prototype wiring system be capable of providing one or more ground plane layers for a prototype circuit. The push-in type prototype wiring system discussed above has no such provision for a ground plane and thus can not be used to model circuits other than very low frequency and low power circuits.